U.S. patent number 7,721,613 [Application Number 10/542,820] was granted by the patent office on 2010-05-25 for method of mounting a retaining ring on an electric starter shaft comprising a starter drive assembly and corresponding starter.
This patent grant is currently assigned to Valeo Equipements Electriques Moteur. Invention is credited to Philippe Halbin, Thierry Paltrie.
United States Patent |
7,721,613 |
Halbin , et al. |
May 25, 2010 |
Method of mounting a retaining ring on an electric starter shaft
comprising a starter drive assembly and corresponding starter
Abstract
The invention relates to a method of mounting a retaining ring
(21) on a rotating electric armature shaft. The inventive method
consists in first mounting the retaining ring (21) on an axial
shaft segment (27) which is located in an accessible mounting area
between the groove (23) and the splines (15) of the starter drive
assembly (10) and, subsequently, moving the starter drive assembly
(10) axially towards the rest position such as to move the
retaining ring (21) along the aforementioned shaft segment (27) as
far as the positioning groove (23) comprising a service area with
no radial access.
Inventors: |
Halbin; Philippe
(Villefontaine, FR), Paltrie; Thierry (Lyons,
FR) |
Assignee: |
Valeo Equipements Electriques
Moteur (Creteil, FR)
|
Family
ID: |
32605912 |
Appl.
No.: |
10/542,820 |
Filed: |
January 21, 2004 |
PCT
Filed: |
January 21, 2004 |
PCT No.: |
PCT/FR2004/000130 |
371(c)(1),(2),(4) Date: |
December 20, 2005 |
PCT
Pub. No.: |
WO2004/067950 |
PCT
Pub. Date: |
August 12, 2004 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20060145481 A1 |
Jul 6, 2006 |
|
Foreign Application Priority Data
|
|
|
|
|
Jan 21, 2003 [FR] |
|
|
03 00644 |
|
Current U.S.
Class: |
74/7R; 74/7C;
74/7A; 74/6 |
Current CPC
Class: |
B25B
27/20 (20130101); F02N 15/006 (20130101); F02N
15/065 (20130101); F02N 15/023 (20130101); Y10T
74/131 (20150115); Y10T 74/132 (20150115); Y10T
74/134 (20150115); Y10T 74/13 (20150115); F16B
21/186 (20130101) |
Current International
Class: |
F02N
15/00 (20060101); F02N 15/02 (20060101); F02N
15/04 (20060101); F02N 15/06 (20060101) |
Field of
Search: |
;74/6,7A,7C,7R |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
0 494 681 |
|
Jul 1992 |
|
EP |
|
2 518 176 |
|
Jun 1983 |
|
FR |
|
2 649 349 |
|
Jan 1991 |
|
FR |
|
667935 |
|
Mar 1952 |
|
GB |
|
1 384 689 |
|
Feb 1975 |
|
GB |
|
61079525 |
|
Apr 1986 |
|
JP |
|
64-39475 |
|
Mar 1989 |
|
JP |
|
4-56295 |
|
May 1992 |
|
JP |
|
5-6154 |
|
Jan 1993 |
|
JP |
|
Primary Examiner: Hannon; Thomas R
Assistant Examiner: Krause; Justin
Attorney, Agent or Firm: Osha .cndot. Liang LLP
Claims
The invention claimed is:
1. A method of mounting a retaining ring on a rotating electric
starter shaft of an electric starter drive assembly, wherein the
electric starter drive assembly comprises: a reducing gear coupled
to the shaft and comprising a protuberance, wherein the starter
drive assembly comprises: a bushing and a pinion to drive a toothed
ring of an internal combustion engine, and a self-disengaging
coupling device acting between the bushing and the pinion and
interposed axially between the reducing gear and the pinion, the
busing and the shaft which penetrates inside the bushing having
splines that cooperate, wherein the retaining ring is a rear stop
arranged on the shaft, and wherein the shaft comprises a front
stop, the front and rear stops being spaced apart thereon to define
a course along which the starter drive assembly slides between a
rest and a working position of the pinion, while being engaged on
the toothed ring, an angular positioning channel provided on a rear
end of the shaft for insertion of the retaining ring which forms
the rear stop, wherein the electric starter drive assembly
comprising the pinion, the self-disengaging coupling device, and
the reducing gear is introduced in a housing of an electric
starter, after the retaining ring is placed in the positioning
channel, starting from a configuration in which the positioning
channel is recessed from the protuberance of the reducing gear in a
service area with no radial access, the method comprising: mounting
the retaining ring radially on an axial segment of the shaft with a
progressive cross-section situated in a radial fitting area in an
accessible mounting area between the positioning groove and the
splines; and moving the starter drive assembly axially toward the
rest position so as to move the retaining ring along the axial
segment of the shaft to the positioning groove, which is located in
a service area with no radial access.
2. The mounting method according to claim 1, wherein the service
area is disposed beneath a protrusion of a speed reducer.
3. The mounting method according to claim 1, wherein a shaft
segment with a cross section that increases toward the positioning
groove is used.
4. The mounting method according to claim 3, wherein a diameter of
the shaft is close or equal to a diameter acceptable by the
retaining ring without elastic deformation of the retaining ring,
wherein the diameter acceptable by the retaining ring is one that
is less than or equal to a diameter of the positioning channel.
5. The mounting method according to claim 2, wherein the service
area is disposed beneath a plurality of protrusions, wherein at
least one protrusion is shorter than other protrusions of the
plurality of protrusions.
Description
TECHNICAL FIELD OF THE INVENTION
The invention relates to a method of mounting a retaining ring on a
rotating electric starter shaft, comprising a starter drive
assembly that includes a self-disengaging coupling device such as a
freewheel unit cooperating with two series of helicoid splines of
complementary shapes arranged respectively on the shaft and a
bushing of a drive hub, which shaft has a first rear stop and a
second front stop spaced apart on the shaft to define the course
along which the starter drive assembly slides between the rest and
working positions, said first rear stop being formed by said
elastic retaining ring inserted into an annular positioning groove
of the shaft.
STATUS OF TECHNOLOGY
FIGS. 1 and 2 show a starter drive assembly 10 of an electric
starter, comprising a drive pinion gear 11 of the ring gear of an
internal combustion engine, such as a motor vehicle. This starter
drive assembly 10 also comprises a bushing 18, called carrier and a
self-disengaging coupling device 12 which in this instance is a
freewheel unit between the pinion gear 11 and the cylindrically
shaped bushing 18. Two series 15, 16 of complementary shaped
helicoid splines are provided. The freewheel transmission device 12
is axially inserted between the pinion gear 11 and a speed reducer
13 comprising an outer ring gear with internal teeth 13a and
cooperating with satellite gears 14 supported on a satellite holder
14b. This speed reducer is coupled to the fluted end of the shaft
of the electric motor as can be seen in FIG. 1 of the document WO
00/39454, to which reference can be made for more details, this
reducer being of the type described in that document. The bushing
18 is integral with a cage 19 pertaining to the freewheel unit 12.
A shaft 17 is coupled to the satellite holder 14b of the reducer
13a. This shaft 17 penetrates inside the bushing 18 and the pinion
11.
The two series of splines 15, 16 are arranged respectively on the
shaft 17 and in the cylindrical bushing 18 of the starter drive
assembly 17. The pinion 17 is thus inter-locked with the bushing 18
by the freewheel transmission device 12, which makes it possible to
drive the pinion 11 during the normal starting phase, and to
disengage the rotating mechanical drive connection when the speed
of rotation of the pinion 11 exceeds that of the bushing 18. When
the combustion engine has started, the presence of the freewheel
device 12 prevents the pinion 11 engaged with the ring gear of the
internal combustion engine from driving the rotor of the electric
motor at an excessive speed that could damage said motor. Such a
situation could occur when the operator of the vehicle does not cut
off power from the switch immediately after starting.
The freewheel unit 12 illustrated in FIG. 1 is of the type with
rollers 20 between a race of the cage 19 integral with the bushing
18 and an inner race attached to the pinion 11. However, it is
clear that any other unidirectional transmission device can be
used, particularly a self-disengaging cone clutch friction coupling
device such as the one described in the document FR 2772433.
At the end of starting, the starter drive assembly 12 tends to
unscrew from the splines 15 of the shaft 17, which causes an axial
force tending to pull the end 25 of the bushing 18 toward a rear
stop attached to the shaft 17, which stop is composed of a
retaining ring 21 situated opposite the pinion 11. This axial
reaction force is added to the retraction forces of the movable
core of the electromagnetic contactor of conventional design, after
power is cut off to said switch, by means of a lever (not shown)
pivoting around an axis and one end of which is in contact with the
movable core and the other free end is fitted in the groove 18a to
drive the starter drive assembly in translation. Such an
electromagnetic contactor and such a lever are described in the
above-mentioned document WO 00/39454. The pinion 11 quickly escapes
from the ring gear with enough speed to avoid wear and
deterioration of the ends of the teeth.
A front stop 22 is arranged on the shaft 17 of the starter drive
assembly to define the end-of-travel position of the pinion 11 when
engaging on the ring gear. The axial interval separating the front
stop 22 and the retaining ring 21 determines the course along which
the starter drive assembly 12 slides between the rest and working
positions, respectively, of the pinion 11.
The retaining ring 22 (FIG. 2) is open, shaped like a "C", with a
thickness on the order of 1 to 1.5 mm. The separation between the
end tips 24 of the C is slightly less than the diameter of the
positioning groove 23 provided at the rear end of the shaft 17 of
the starter drive assembly 10. In the rest position, the end 25 of
the bushing 18 comes to a stop against the retaining ring 21.
The usual rules for mounting this type of circlips consist of
exerting a radial thrust (arrow F, FIG. 1) on the middle part of
the ring 21 to insert it in the positioning groove 23 in a
direction perpendicular to the shaft 17. The pinching of the tips
24 after insertion allows the retaining ring 21 to be held stably
in the groove 23.
Such a radial mounting of the retaining ring 21 of a known starter
drive assembly is only possible if the positioning groove 23 is
accessible vis-a-vis the protrusion 26 of the speed reducer 13.
These protrusions 26 consist for example of elastic shock-absorbing
bumpers 13b held in seats 50a of the housing 50 (partially shown)
of the starter. These elastic means 13b therefore allow rotating
movement which makes it possible to absorb the shocks and thus
reduce the noise. For additional details, reference can be made to
the document WO 00/39454. As a variation of embodiment, these
protrusions 26 can be made of non-elastic bumpers.
The assembly composed of the pinion 11, the self-disengaging
coupling device 12 and the speed reducer 13 is inserted, after
placing the retaining ring 21 in its groove 23, into the housing 50
of the starter.
The shaft 17 of the starter drive assembly 10 should be axially
lengthened a distance L to allow the insertion of the retaining
ring 21. The result is an increase in the longitudinal size of the
starter.
PURPOSE OF THE INVENTION
A purpose of the invention is to reduce these disadvantages, and to
establish a mounting method to facilitate the insertion of the
retaining ring of a starter drive assembly with stops on splines
without the need to lengthen the shaft of the starter.
According to the invention, in a first step the retaining ring is
first mounted on an axial segment of shaft in an accessible
mounting area between the groove and the splines, and in a second
step, the starter drive assembly is moved axially toward the rest
position so as to move the retaining ring along the segment of
shaft to the positioning groove, which is made in a service area
with no radial access.
The retaining ring is inserted radially on the shaft in an area
free of any surrounding parts, and a manual movement of the starter
drive assembly then pushes the ring into the groove, set back where
radial access would not be possible. Such mounting makes it
possible to reduce the longitudinal size of the starter.
The invention also relates to an electric starter for a motor
vehicle equipped with a starter drive assembly comprising a
self-disengaging coupling device, such as a free-wheel unit
cooperating with two series of helicoid splines of complementary
shape made respectively on the shaft and in a bushing of a drive
hub, a first rear stop and a second front stop spaced apart on the
shaft to define the course along which the starter drive assembly
slides between the rest and working positions, said first rear stop
being formed by said elastic retaining ring inserted into an
annular positioning groove of the shaft. The positioning groove is
advantageously placed in a private service area with radial access,
and below a protrusion from the speed reducer.
The device can be advantageously supplemented by one or more of the
following features:
the positioning groove has a front face intended to axially block
the retaining ring in the service area;
the positioning groove is delimited opposite the front face by an
annular stop face, the width of which is greater than that of the
front face;
the axial length of the groove separating the front face from the
stop face is selected in order to seat one or more elastic
retaining rings;
the positioning groove is axially separated from the splines of the
shaft of the starter drive assembly by a conically shaped segment
of shaft, the diameter of the side of the splines being less than
the diameter near the front face of said groove.
SUMMARY DESCRIPTION OF THE DRAWINGS
Other advantages and characteristics will be seen more clearly from
the following description of a mounting method according to the
invention, given by way of non-limiting example, and represented in
the attached drawings in which:
FIG. 1 shows a cross sectional view of the starter drive assembly
of a starter of the prior art;
FIG. 2 is a detailed view of the retaining ring comprising the rear
stop of the starter drive assembly shaft;
FIG. 3 is a diagrammatic half-view in cross section and in larger
scale of part of the starter drive assembly shaft allowing the
implementation of the mounting method according to the
invention;
FIGS. 4 and 5 represent views identical to that of FIG. 1,
illustrating the steps according to the invention of mounting the
retaining ring, in the event of no access to the positioning groove
according to FIG. 3.
DESCRIPTION OF AN EXAMPLE OF EMBODIMENT ACCORDING TO THE
INVENTION
In FIGS. 3 to 5, the same reference numbers will be used to
designate similar or identical parts to those in FIGS. 1 and 2.
With reference to FIG. 3, the positioning groove 23 of the shaft 17
of the starter drive assembly is axially separated from the inner
splines 15 by a segment of shaft 27 with a progressive, such as
conical, cross section. The diameter D1 of the shaft segment 27 of
the side of the splines 15 is less than the diameter D2 near the
front face 28 of the groove 23. The front face 28 is appreciably
perpendicular to the longitudinal axis of the shaft 17, but can
also be sloped and can have a non-rectilinear profile.
The diameter D1 of the shaft segment 27 is close to the diameter
acceptable by the retaining ring without elastic deformation of
said ring. Preferably, the diameter D1 is equal to the diameter D3
of the bottom of the groove 23 recommended by the manufacturer of
the ring.
Opposite the front face 28, the groove 23 is delimited by an
annular stop face 29, the width of which corresponds to the
difference of the diameters D4 and D3. This width is sufficient to
resist the axial thrust due to the return of the starter drive
assembly to rest position, and is greater than the width of the
front face 28 corresponding to the reference of diameters D2 and
D3. Advantageously, the face 29 pertains to an increased thickness
that the shaft 17 has for attaching it to the satellite holder 14b.
This increased thickness is of a greater diameter than that of the
segment 27.
The radial mounting area of the elastic retaining ring 21 is
accomplished in a first step in the axial space d situated between
the protrusion 26 and the end of the splines 15. This space d
allows the insertion of the ring 21 on the accessible part of the
shaft segment 27.
FIG. 4 illustrates this first step of inserting the retaining ring
into the accessible space. The ring 21 is simply pushed radially
onto the shaft segment 27, as in FIG. 1. The protrusion 26 does not
hinder this mounting operation. Advantageously, as can be seen in
FIGS. 4 and 5, the protrusions 26 do not all have the same shape.
Some of these protrusions are shorter to reduce still more the
axial length of the shaft 17 and to allow the easy mounting of the
circlips.
To transfer the retaining ring 21 into the positioning groove 23
beneath the protrusion 26, the starter drive assembly 10 is moved
in the direction of the arrow F1 so that the rear end 25 of the
bushing 18 axially pushes the ring 21 along the shaft segment 27
toward the reducer 13 until engaging it in the positioning groove
23. It is thus possible to insert the retaining ring 21 in the
positioning groove 23 located in a private service area with radial
access, and without increasing the longitudinal size of the
starter. As it moves along the shaft segment 27, the ring 21 opens
progressively, then recloses when it falls into the groove 23.
Obviously, without going beyond the scope of the invention, the
protrusions 26 can consist of any construction other than elastic
bumpers (for example, made of elastomer) or of plastic intended to
cooperate with the housing of the starter. For example, it could be
a projection from the outer ring of the speed reducer. Protrusion
should be understood as any device that prevents direct radial
access to the groove 23 intended to seat the stop 21.
* * * * *